Stock wiring harness in 1998 Pontiac Bonneville

I have a 1998 Pontiac Bonneville SSE and it originality had a Bose system in it i am trying to put a valor multimedia in it i had a friend who had no f****** clue what he was doing and cut the stock wiring harness on my car an i need to know how to re hook up my stock wiring harness and my valor into my car once i have my stock harness hooked back up to the car i had a lot of problems with the sound coming out of the valor so i had my friend help me which he had no clue what he was doing so yea i really need some help with this...